Cummins/Onan 10HDKAG Generator Set

⚠ Do not operate the genset without the belt guard in place.

⚠ Accidental starting can cause severe personal injury or death; disconnect battery cables.

Tools: Belt guard removal tools

1. Disconnect starting battery cables, negative cable first.
2. Remove the belt guard from the front of the set.
3. Loosen the bolt passing through the long slot in the alternator mounting bracket.
4. Slide the alternator until tension is correct.
5. Check deflection is about 0.4 inch (10 mm) with 22 pounds (10 kg) finger pressure.
6. Reinstall belt guard.

⚠ Batteries present explosion hazard; do not smoke or allow ignition sources.

⚠ Battery electrolyte can cause severe eye damage and burns to skin.

Tools: Battery hydrometer, Terminal puller tool

1. Keep battery case clean and dry.
2. Make certain cable connections are clean and tight; remove corrosion.
3. Wash terminals with ammonia solution or 1/4 lb baking soda in 1 quart water.
4. Add distilled water to the split-level marker in each cell.
5. Check specific gravity with hydrometer; charge if below 1.215.
6. Stop charging when specific gravity reaches 1.260 at approximately 80 °F (27 °C).
7. Always connect the negative cable last.

⚠ This procedure must be done by a Cummins Onan service center or a professional diesel technician.

⚠ Dirt or water in the system will cause severe damage to the injection pump and nozzles.

1. Loosen the fittings of the low-pressure fuel lines one by one.
2. Crank the electric fuel pump to drive out trapped air.
3. The high-pressure system is self-priming; trapped air is forced out through the injection nozzles.

⚠ Many cleaning solvents present a hazard of severe personal injury or death.

Tools: Suitable solvent

1. Remove cap nuts and gaskets from top of valve cover; remove cover without damaging gasket.
2. Remove two machine screws securing breather element, plates and shield.
3. Clean element in suitable solvent, dry, then saturate with engine oil.
4. Clean other breather components in solvent if necessary.
5. Reassemble.

⚠ Exceeding the recommended fill rate can cause incomplete filling of the engine block.

⚠ Coolant in a warm engine is under pressure and can flash to steam causing severe burns.

1. Verify all drain cocks are closed and hose clamps secure.
2. Remove pressure cap and slowly fill with 50/50 coolant mixture.
3. Add coolant to recovery tank to full-cold level.
4. Start engine, remove pressure cap and monitor coolant level.
5. Add coolant as trapped air is expelled and level drops.
6. Replace pressure cap when coolant level is stable.

⚠ Contact with hot coolant can cause severe burns.

⚠ Never pour hot water into a cold engine or cold water into a hot engine.

1. Once a year drain, flush and refill with new coolant.
2. Open radiator coolant drain and cylinder block drain at rear of engine.
3. Clean with a good cleaning compound if rust and scale collected.
4. Drain, fill with clean water, run genset 10 minutes, then drain completely.
5. Refill with the coolant mixture.

⚠ Spark arrester must be periodically cleaned to meet Forest Service requirements.

1. Remove the 1/8 inch pipe plug from the bottom of the muffler.
2. Run the generator set with a full load for five minutes.
3. Stop the generator set and allow the muffler to cool.
4. Replace the pipe plug in the muffler.

⚠ Hot crankcase oil can cause burns.

⚠ Prolonged contact with used engine oil can cause cancer or reproductive toxicity.

Tools: Oil drain container

1. Run engine until thoroughly warm, then stop the engine.
2. Open the drain valve and drain oil into a container.
3. Close the valve and refill crankcase with new oil.
4. Spin off oil filter and discard it; clean mounting surface.
5. Apply thin film of oil to filter gasket and spin on until gasket touches pad.
6. Turn filter an additional 3/4 turn; do not over-tighten.
7. Start set and check for leakage around filter gasket.

⚠ Battery electrolyte can cause severe eye damage and burns to the skin.

Tools: Trickle charger

1. Exercise the genset until engine reaches operating temperature.
2. Shut down and disconnect battery cables, negative first; store battery cool and dry.
3. Trickle charge battery once every 30 days.
4. Drain crankcase oil while warm, replace oil filter, refill and tag oil viscosity.
5. Check coolant level and test mixture if freezing temperatures are possible.
6. Plug the exhaust outlet.
7. Clean and wipe entire genset; lightly coat rust-prone parts with grease or oil.

⚠ DO NOT OVERCHARGE the battery.

⚠ Wear goggles, rubber gloves and a protective apron when working with batteries.

Tools: Battery hydrometer

1. Remove the plug from the exhaust outlet.
2. Verify oil viscosity is still correct for existing ambient temperatures.
3. Clean and check the battery; measure specific gravity (1.260 at 80 °F [27 °C]).
4. Prime the fuel system.
5. Connect the starting battery, negative cable last.
6. Remove all loads before starting the genset.
7. After starting, apply load of at least 50 percent rated capacity.
8. Check all gauges for normal readings.

⚠ Preheat time longer than 30 seconds may damage glow plugs.

⚠ Do not engage the starter longer than 30 seconds without allowing two minutes for cooling.

1. Press Start/Stop/Preheat switch to Stop/Preheat and hold 10 to 30 seconds depending on temperature.
2. Press switch to Start; release when engine starts.
3. If engine does not start after cranking 30 seconds, release and wait two minutes.
4. Repeat preheat and start.
5. If second try fails, check fuel supply and that fuel system is primed.

⚠ Failure to allow running time for engine cooling without load can cause engine damage.

1. Run the genset at no load three to five minutes before stopping.
2. Press the Start/Stop/Preheat switch to Stop.
3. Hold stop down until AC voltage falls below the control's minimum operating level.